SpringBoot整合Mybatis-plus多数据源

背景说明：在项目中需要访问多个数据库的时候，我们该怎么办呢？下面我介绍一个极其方便的动态切换数据源的方法。

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo-spring-mybatisplus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo-spring-mybatisplus</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- mybatis-plus 需要引入的包 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.1</version>
        </dependency>

        <!-- mybatis-plus配置不同数据源 需要引入的包 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>3.3.2</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.21</version>
        </dependency>

        <!-- 阿里云连接池 配置文件在 spring.autoconfigure.exclude 引入 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.8</version>
        </dependency>

        <!-- 引入lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.16</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.yml

spring:
  autoconfigure:
    exclude: com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure
  datasource:
    dynamic:
      primary: mysql1 #设置默认数据库源
      strict: false #严格匹配数据源，默认为false，true未匹配到指定数据库时抛异常，false使用默认数据源
      datasource:
        mysql1:
          driver-class-name: com.mysql.cj.jdbc.Driver
          url: jdbc:mysql://localhost:3306/demo_mybatisplus?serverTimezone=UTC
          username: root
          password: root
        mysql2:
          driver-class-name: com.mysql.cj.jdbc.Driver
          url: jdbc:mysql://localhost:3306/demo_mybatisplus2?serverTimezone=UTC
          username: root
          password: root

com.example.demospringmybatisplus.pojo

@Data
@NoArgsConstructor //生成无参构造函数
@AllArgsConstructor //生成全参数构造函数
@ToString
@TableName(value = "user") //指定查询的表名为user
public class User {
    // 以下为 mybatis-plus测试
    private Integer id;
    private String name;
    private String password;
    private String sex;
    private Date createTime;
    private Date updateTime;
}

@Data
@NoArgsConstructor //生成无参构造函数
@AllArgsConstructor //生成全参数构造函数
@ToString
@TableName(value = "user") //指定查询的表名为user
public class User2 {
    // 以下为 mybatis-plus测试
    private Integer id;
    private String name;
    private String password;
    private String email;
}

com.example.demospringmybatisplus.mapper

@DS("mysql1")
@Repository("UserMapper")
public interface UserMapper extends BaseMapper<User> {
}

@DS("mysql2")
@Repository("User2Mapper")
public interface User2Mapper extends BaseMapper<User2> {
}

项目启动类：DemoSpringMybatisplusApplication

@MapperScan("com.example.demospringmybatisplus.mapper")
@SpringBootApplication
public class DemoSpringMybatisplusApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoSpringMybatisplusApplication.class, args);
    }
}

项目测试类：DemoSpringMybatisplusApplicationTests

@SpringBootTest
class DemoSpringMybatisplusApplicationTests {
    @Autowired
    UserMapper userMapper;
    @Autowired
    User2Mapper user2Mapper;
    @Test
    void contextLoads() {
        User user = userMapper.selectById(1);
        System.out.println(user.toString());
        User2 user2 = user2Mapper.selectById(1);
        System.out.println(user2.toString());
    }
}

项目运行截图（DemoSpringMybatisplusApplicationTests启动）：

项目已经上传到 GitHub 和 Gitee

GitHub：demo-spring-mybatisplus

Gitee：demo-spring-mybatisplus